Drs. Lee Ghin and Barna are both clinical assistant professors in the Department of Pharmacy Practice and Administration, Ernest Mario School of Pharmacy, Rutgers—The State University of New Jersey, Piscataway, New Jersey.
In OAB, the detrusor, or bladder muscle, inappropriately contracts and prevents the bladder from completely filling. This leads to sudden, forceful, and often unpredictable urges to urinate and sometimes results in premature urinary leakage. Additionally, neurologic conditions, such as dementia, stroke, or spinal cord injury, bladder irritation, and medications, including diuretics, can also cause impaired detrusor muscle stability. In 2002, the International Continence Society classified OAB as a symptom-based syndrome defined as urinary urgency, with or without urge incontinence, usually with frequency and nocturia in the absence of infection or other proven pathology. Urge incontinence affects only one third of the entire OAB population (OAB wet), whereas two thirds have OAB without urge incontinence (OAB dry).2
Therapeutic interventions for OAB consist of lifestyle modifications, drug therapy, and surgery. Lifestyle or behavioral techniques are considered first-line treatment for most types of OAB and are generally associated with no adverse effects. Pelvic floor muscle training exercises (eg, Kegel exercises) can be taught to patients by their physicians during a routine urological examination or can be learned from patient educational materials.4 These exercises can be augmented by the use of biofeedback to help patients learn to selectively contract and strengthen pelvic muscles to tighten the bladder outlet and cope with symptoms of urinary urgency.5 In addition to pelvic floor training, educating patients about bladder functioning, fluid intake management, including the timing of fluid intake and maintenance of hydration, management of constipation, and dietary alterations, such as decreasing caffeine or alcohol consumption, are other nonpharmacologic interventions that are reported to improve symptoms of OAB. For older patients or patients with cognitive impairment or limited mobility, toileting assistance, use of bedside commodes, or prompted voiding may additionally alleviate symptoms of OAB.6 These changes should always be incorporated into a patient's treatment plan as they have been proven to be beneficial.7-10 Patients' expectations of treatment also should be addressed, as this can have a negative impact on treatment outcomes as well as medication adherence.11,12 Pharmacologic interventions for OAB are generally noncurative, and nonadherence can result if treatment results do not meet the patient's expectations.
Anticholinergic or antimuscarinic medications are the mainstay of pharmacologic treatment for OAB. These agents work to improve detrusor muscle function by competitively antagonizing the effects of acetylcholine on bladder muscarinic receptors to improve symptoms of incontinence. The Table includes a list of available medications in this class and their respective formulations and strengths. One of the major limitations of using immediate-release products in the management of OAB is the higher incidence of adverse effects (eg, dry mouth, constipation, headache, blurred vision, and drowsiness), which may result in patients preferring to cope with their symptoms rather than take the medication. For patients who are unable to take oral medications, oxybutynin also is available as an extended-release transdermal patch. This formulation is associated with a lower incidence of dry mouth and constipation than any of the oral preparations. All of these agents are contraindicated in patients with closedangle glaucoma or gastric retention.
In controlled studies, all of these products have been proven efficacious in reducing symptoms, with the extended-release products offering better patient adherence.8,13 No head-to-head clinical study comparisons of the extended-release formulations of these products have been completed, making direct efficacy comparisons of these products difficult.
A variety of medical devices are available for alleviating symptoms of OAB, including continence pessaries, urethral plugs, magnetic and electrical stimulation interventions, and self-catheterization. For patients with severe symptoms, or those who have failed nonpharmacologic or pharmacologic therapies, several surgical modalities also are available. These procedures are not first-line interventions, and the type of procedure is dependent on the type of incontinence the patient is experiencing.
When discussing the condition of OAB with a patient, the pharmacist needs to be sensitive to this treatable, but often embarrassing, medical condition. Realizing the sensitive nature of this condition and the fact that patients may attempt self-treatment without the guidance of a primary care physician, pharmacists must inquire about medical evaluation before recommending other interventions or offering advice on OTC incontinence aids. Patients should be advised to seek medical attention if frank incontinence occurs, if the urge to void occurs more than twice a night, or if pain or hematuria is present.
For patients diagnosed with OAB, recommending avoidance of aggravating factors is an important first step in symptom improvement. Lifestyle interventions, including smoking cessation and weight loss, may also improve OAB symptoms. Discussing the importance of performing pelvic floor exercises and bladder training techniques with a primary care physician should be emphasized.
Regarding the anticholinergic agents that are commonly prescribed for OAB, patients and caregivers should be cautioned about the potential for these agents to cause bothersome symptoms of dry mouth and constipation. These medications can additionally affect the central nervous system and can cause altered mentation, hallucinations, somnolence, and confusion, especially in the elderly population. Patients reporting intolerance to side effects of immediate-release preparations should be advised to discuss with their physician the possibility of switching to an extended-release or alternative formulation that may be associated with fewer side effects.
Patients with symptoms of OAB may seek pharmacist recommendations for absorbent undergarments to help manage urinary overflow. Although these products are helpful in the management of OAB, absorbent products should be used in conjunction with other therapeutic modalities, including medications. Inappropriate use of these products can result in delays in diagnosis and treatment and can also increase the risk of skin breakdown. When asked for a recommendation on such a product, pharmacists have an opportunity to address patient concerns about their disorder, including advising patients to seek further medical evaluation from a physician, discussing potential bothersome adverse effects, as well as providing helpful educational materials.
OAB affects the quality of life of millions of Americans. Pharmacists are well positioned to educate patients regarding nonpharmacologic and pharmacologic interventions and to recommend OTC products for managing incontinence, when appropriate.